We've all seen the adorable panda pictures of these cuddly black and white bears lazing around chewing on bamboo. Just like Forest Gump and Jenny, love and marriage, and a horse and carriage, pandas and bamboo go together like peas and carrots. Or do they? New research suggests it isn't that simple. According to the study from the Chengdu Research Base of Giant Panda Breeding in China, even though the breed has shifted to a plant based diet and has survived on it for the last two million years, it seems their gut bacteria hasn't quite caught up. It still contains bacteria that is best suited to breaking down heavy proteins more common in a carnivorous diet.
Zhihe Zhang, lead author of the new study and director of Chengdu said in a statement about the research, "Unlike other plant-eating animals that have successfully evolved anatomically-specialised digestive systems to efficiently deconstruct fibrous plant matter, the giant panda still retains a gastrointestinal tract typical of carnivores. The animals also do not have the genes for plant-digesting enzymes in their own genome. This combined scenario may have increased their risk for extinction."
As if the Giant Panda doesn't have enough issues. They face extinction in the wild, their habitat is disappearing, they don't breed well in captivity, and now the one food source that is plentiful in their surroundings cannot give them the energy they need to truly thrive. In order to merely survive, most pandas consume about 27 pounds of bamboo leaves and shoots, but scientists discovered that the lack of the appropriate gut bacteria to digest the plant means that less 17% of the nutrients in the plant get digested properly. The time the bears don't spend eating is spent sleeping because they simply don't have the energy for more activity than that.
The study, which was published in the American Society for Microbiology Journal mBio examined the bacteria present in 121 fecal samples taken from 45 of the pandas living at Chengdu. Their results revealed the presence of protein digesting bacteria like Escherichia/Shigella and Streptococcus, but lacked the kind of gut flora like Ruminococcaceae and Bacteroides that are efficient at digesting plant material.
Researchers are now left wondering if the nutritional deficiencies are part of the reason it's so difficult for the pandas to breed easily. To begin with, females only ovulate once a year, normally in the springtime and once that has happened there is a very narrow range of time where they can conceive, at the most, two or three days. If two pandas actually mate, and the egg is fertilized there is then a period of limbo for the embryo, known as "delayed implantation", sometimes lasting as long as two months before attaching and beginning to grow. This study raises the question of nutrition and the fuel needed to successfully nurture a pregnancy. When any animal does not have the kind of food its body is genetically equipped to process, full health is difficult to achieve, much less healthy reproduction.
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